Compound Cannulator for Dialysis Infiltration Risk Reduction

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Solution Overview

Problem

Existing dialysis needles with rigid, sharp tips can cause infiltration or puncture of blood-vessel walls due to incorrect advancement or patient movement during dialysis.

Innovation Solution

A cannulator device comprising a compound needle with a guidewire actuator, a flexible cannula, and a furcated hub, designed for safe cannulation of arteriovenous fistulas, featuring a guidewire actuator to advance or retract the guidewire and a flexible cannula for enhanced patient comfort, with a mated state ensuring secure connection and reduced risk of infiltration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid sharp-tipped dialysis needle is used, then needle strength and puncture capability are improved, but the risk of infiltration and vessel wall damage increases

Engineering Contradiction:
Improveneedle strengthVSAvoidinfiltration risk
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The device is divided into distinct functional segments: a sharp-tipped needle for initial puncture, a separate dilator for vessel dilation, and a flexible catheter for maintained access. This segmentation allows each component to perform its specific function optimally while eliminating the need to leave a sharp needle in place.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sharp needle performs the preliminary action of creating the initial puncture, followed immediately by the dilator that enlarges the opening and the catheter that maintains access. The needle is withdrawn after its preliminary puncture function is complete, preventing infiltration risks during the extended dialysis procedure.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a sharp-tipped needle is left in place during dialysis, then access is maintained, but patient movement can cause infiltration

Engineering Contradiction:
Improveaccess maintenanceVSAvoidinfiltration from patient movement
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The catheter is designed with flexible, dynamic properties that allow it to accommodate patient movement without causing infiltration. Unlike a rigid needle that maintains a fixed sharp tip position, the flexible catheter can move with the patient while maintaining vascular access.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The harmful sharp needle tip is extracted from the system after serving its purpose of initial puncture. Only the safe, flexible catheter remains in place during dialysis, eliminating the source of infiltration risk while maintaining reliable vascular access.

Inventive Principle:
Principle #2Taking out (Extraction)

3Manufacturing precision

If a rigid needle is used for cannulation, then puncture precision is achieved, but patient comfort during prolonged dialysis is reduced

Engineering Contradiction:
Improvepuncture precisionVSAvoidpatient comfort
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The device segments the puncture function (sharp needle) from the comfort function (flexible catheter). The needle provides precise puncture capability, while the flexible catheter provides patient comfort during the prolonged dialysis procedure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The material parameter changes from rigid (needle) to flexible (catheter) after puncture. The catheter is made of flexible polymeric material that increases patient comfort during dialysis while maintaining the precise access established by the initial needle puncture.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4138976B1Cannulators and methods thereof
Publication Date: 2025.09.17 BARD PERIPHERAL VASCULAR INC
  • EP4138976B1 patent drawingFigure 1
  • EP4138976B1 patent drawingFigure 2
  • EP4138976B1 patent drawingFigure 3~4

AI summary

A cannulator (100) can include a compound needle (104) and a compound cannula (102). The compound needle can include a needle (110), a dilator (108), and a needle hub (106). The dilator can be disposed over the needle with at least a tip of the needle extending beyond a distal end of the dilator. The needle hub can be around a proximal-end portion of the dilator. The compound cannula can include a cannula (140) and a cannula hub (142) around a proximal- end portion of the cannula. The cannulator can have a mated state of the compound needle and the compound cannula for at least cannulation with the cannulator. The mated state of the cannulator can include the dilator disposed in the cannula with a proximal-end portion of the cannula hub coupled to a distal-end portion of the needle hub.